Without knowing which version you have, here are the guesses. 1) 1A contactor or coil shorted.
Close. I found this one the old fashioned way: Traced it out.First I started with blowing a bunch of fuses to find the symptom. The tractor could power on, 1A and 2A would work, but as soon as FR clicked down and the first speed switch was closed, it would blow the fuse.
I know I have a ground fault now (it's insane: I can measure voltage to frame even with the main switch off, however the only place it is at zero volts is between the rear two batteries. Everywhere else it's a function of 6 volts up or down the ladder) so this was probably a double fault.
Checked the wires coming off the FR relay to the 1F contactor. Sure enough 0 ohms to ground. Great. Started taking off wires one at a time, went over to the 1R contactor and found that even removing all the wires from the contactor stud would result in a zero ohm reading on the stud.
Wire did not go bad, the contactor coil appears to have shorted to ground. Great...
So this evening I pulled out the contactor pair (what a pain in the $*&$#@&*) and put a spare in. I'll finish tightening the bolts tomorrow, it is a screaming pain to put those in and it's always the case that at least one wire is mis-connected.
I'd love to find that other fault. However I think what everyone really needs is a ground fault detector system of some sort. Not to stop the tractor, but to light an LED or something if there is a single fault.
Chris